1. Field of the Invention
The present invention is directed to a method and an apparatus for evaluating a sequence of medical examination images successively presented at a viewing device by means of a data processing device running on software having an evaluation algorithm for determining image regions exhibiting abnormalities.
2. Description of the Prior Art
Technical progress in medical technology has lead to a great increase of examination results in image form. There is a tendency to implement series examinations at a large number of patients, with a few images, for example, four examination images, being respectively for each patient. This is the case implemented, for example, in mammography and in lung examinations for detecting tuberculosis. By contrast, there are examination methods wherein tens of thousands of examination images from a single patient arise. Examples of this are tomography, MR, angiography and spiral CT. In all of these examination methods, an extremely high amount of data arises in the form of images that must be subsequently analyzed in order to determine pathological changes or abnormalities.
In particular, examination images of series examinations can be interpreted by machine in the meantime. To that end, the examination image, for example an x-ray film, is digitalized and analyzed in a data processing device running on software. The software program determines regions having characteristic structures in the digital image data and compares these to known patterns in order to recognize peculiarities or changes of an organ or of a tissue. Specific clinical pictures are distinguished by characteristic geometrical phenomena; for example, breast cancer can be recognized in an early stage on the basis of calcium agglomerations, referred to as micro-calcifications. After the discovery of a suspicious image region, this can be optically marked on a picture screen, for example by dot markings or the center of several points by a geometrical figure. This method, however, is not 100% reliable, so that all images must be monitored by a physician. Due to the large number of images, it can easily occur that images having abnormalities are overlooked, since the individual images are viewed for only a very brief time. Since the individual images differ only in terms of their details, fatigue often occurs after some time during this procedure, so that images having abnormalities can be overlooked. There is therefore the risk that examination images having symptoms of diseases are not recognized.